Answer:
Step-by-step explanation: 
The answer to this is 1 or 7: 
 
To find the range for the number of measures played to satisfy our solution, we must solve for x using s = 80. 
 
Next, we subtract 50 from both sides of the equation. 
 
Next, we divide both sides of the equation by 10 
 
Next, to eliminate the absolute value bars, we will add a ± sign in front of our s value, 3. 
 
Finally, we add 4 to both sides of our equation giving us 4 ± 3 = x 
 
Separating this into two equations, we get 4 - 3 = x and 4 + 3 = x 
 
Therefore, x, the number of measures of music played, must be either 1 or 7.